Data run programming

Abstract

Data in data runs are stored in a non-volatile memory array in adaptive metablocks that are configured according to the locations of data boundaries. A serial flash buffer is used to store some data, while other data are directly stored in non-volatile memory. Data may be stored with alignment to data boundaries during updating of the data to improve efficiency of subsequent updates.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is a continuation-in-part of application Ser. No. 10 / 841,118, by Alan Welsh Sinclair, filed on May 7, 2004, which is a continuation-in-part of application Ser. No. 10 / 749,189, by Alan Welsh Sinclair, filed on Dec. 30, 2003, which applications are hereby incorporated by reference in their entirety.BACKGROUND.[0002]This invention relates generally to the operation of non-volatile memory systems, and, more specifically, to the handling of data within such memory systems.[0003]There are many commercially successful non-volatile memory products being used today, particularly in the form of small form factor cards, which employ an array of flash EEPROM (Electrically Erasable and Programmable Read Only Memory) cells formed on one or more integrated circuit chips. A memory controller, usually but not necessarily on a separate integrated circuit chip, interfaces with a host to which the card is removably connected and controls oper...

AI Technical Summary

Benefits of technology

[0016]Data may be stored in a memory array in adaptive metablocks. The size of an adaptive metablock may be tailored to the data to be stored. Adaptive metablock size may be determined based on the nature of the data (control data, data from host) or may be determined based on boundaries within the data, such as boundaries between files. Configuring adaptive metablocks according to the data reduces the effects of logical fragmentation.

[0017]Logical groups that contain data equal to the data in one erase block of a memory array are formed from logically sequential sectors. Adaptive logical blocks are formed from logical groups. Adaptive logical blocks may contain different numbers of logical groups. Individual adaptive logical blocks are stored in individual adaptive metablocks in a memory array. The number of erase blocks in an adaptive metablock is equal to the number of logical groups in the corresponding adaptive logical block. Thus, an adaptive metablock has a variable number of erase blocks. The erase blocks of a metablock may be from fewer than all the planes of the memory array. More than one adaptive metablock may be programmed at one time. Adaptive metablocks may be formed according to the data to be stored. Large adaptive metablocks may be used to attain a high degree of parallelism during programming. Smaller adaptive metablocks may be used to allow efficient updating of stored data.

[0018]Adaptive logical blocks may be formed so that boundaries between adaptive logical blocks reflect boundaries in the data, for example boundaries between files or streams of data. By tailoring adaptive logical blocks in this way, copying of data within the memory array may be reduced. Where data is updated, a new adaptive logical block may be formed to hold the updated data with a small amount of old data. Thus, if the same data is updated again, there is only a small amount of old data that needs to be copied.

Problems solved by technology

These storage levels do shift as a result of charge disturbing programming, reading or erasing operations performed in neighboring or other related memory cells, pages or blocks.

Also, shifting charge levels can be restored back to the centers of their state ranges from time-to-time, before disturbing operations cause them to shift completely out of their defined ranges and thus cause erroneous data to be read.

Zones are primarily used to simplify address management such as logical to physical translation, resulting in smaller translation tables, less RAM memory needed to hold these tables, and faster access times to address the currently active region of memory, but because of their restrictive nature can result in less than optimum wear leveling.

Copying unchanged sectors may add to the time required for copying and adds to the space occupied by the data in the memory array because the original metablock may not be used until an erase operation is performed.

Thus, logical fragmentation becomes a greater problem as metablocks become larger.

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